Brain Registers Subliminal Nude Images

This is one of those experiments that must have raised a few eyebrows during the approval process… “Let’s get this straight, you are going to show subjects invisible pictures of naked people and see if they unconsciously remember seeing them…” Apparently, though, the research got the go-ahead and ended up producing surprising results. Cognitive neuroscientist Sheng He of the University of Minnesota was part of a team that presented subjects with images of nude men and women by showing separate images to each of their eyes. The images exploited an odd quirk in the way humans process visual information:

The researchers took advantage of a phenomenon called binocular rivalry to make the erotic images invisible. When two very different images are presented to each eye separately, the images will alternate between one image and the other. But if one eye is exposed to an image and the other to dynamic visual “noise,” the noise will suppress the image and render it essentially invisible to the viewer.
(from LiveScience, Erotic Images Entice Even When Invisible)

The high-contrast image used in these tests is called a Gabor patch. The experimenters found that even though the subjects were unaware that they had seen the erotic image, they registered its location and were more successful at determining the orientation of a Gabor patch shown briefly in the same place. ScientificAmerican.com reports in Subliminal Nude Pictures Focus Attention:

Into the canceled out image slot, the researchers slipped an erotic image; for example, a naked woman displayed for a heterosexual man. To ensure that subjects did not consciously detect the invisible image, they were asked to press a specific key if they noticed any difference between the left and right images. Over the course of 32 trials, men were significantly better at detecting the orientation of Gabor patches when they appeared in the slot formerly occupied by an invisible image of a nude woman.

Decades ago, author Vance Packard wrote the best-selling title, The Hidden Persuaders, which focused on the potential power and misuse of subliminal advertising. Some years after that, there was a flurry of interest in the topic when another author claimed to find hidden erotic images and faintly printed obscene words in many popular advertisements. Everyone else apparently lacked the latter author’s unique ability to see these images, and the topic faded into obscurity.

What are the neuromarketing implications of this new research? On a direct basis, there really aren’t any. The unique and cumbersome means the experimenters used to present the subliminal images simply aren’t going to occur in the real world, nor would most advertisers seek to employ such an approach even if it were somehow possible. I think the findings ARE important for marketers in one respect, however – they serve as a clear reminder that we all DO process information without being consciously aware of it.

That we accept subconscious input isn’t exactly news, but it’s a fact often forgotten by marketers. When we view an advertisement, for example, there’s a lot going on under the surface. A good example of this is the rapidity of processing a web site upon arrival, as we reported in Neuroscience and Web Design; viewers form an impression in a fraction of a second, far too quickly for cognitive processing of the actual page content. This means that self-reporting (interviews, focus groups, surveys, personal logs, etc.) may be inaccurate even when the individual is doing his best to report accurately and truthfully. (“Naked woman? What naked woman? I’m sure I would have noticed THAT kind of picture! Nope, I’m positive I didn’t see it.”)

Whenever possible, marketers need to use absolute measures of results – actual sales, showroom visits, time-on-site, etc. as indicators of the effectiveness of advertising. Even when people WANT to tell the truth, they may not be able to. Measure their behavior instead of asking them.

The other important point is to be aware of every element of an advertisement (or marketing campaign, sales call, etc.). We expect customers to look at what we want them to look at – the catchy headline, the clever copy, the product photo – but they are registering a lot more information. The look and feel of the ad, the background, the font, the body language of the model, and many other aspects are processed – very quickly, and mostly unconsciously. In some cases, these may not be particularly important, but if one or more elements creates dissonance with the intention of the ad, the ad’s performance could be affected. (Ultimately, the boon of fMRI studies may be to help understand how the subliminal aspects of an ad are received – that would indeed be a benefit to the marketing community.)